Effects of acute resistance exercise with different loads on appetite, appetite hormones and autonomic nervous system responses in healthy young men.

Although the effect of continuous aerobic exercise on the appetite has been widely explored, the influence of resistance exercise (RE) with different variables, including training loads, training volume, and inter-set rest, on appetite responses requires further investigation. This study examined the importance of training load in RE-induced appetite regulation, with the total training volume and inter-set rest equalized. In total, 11 healthy young men (age = 23 ± 2 years, body mass index = 22 ± 2 kg/m2) were included. Participants completed 3 trials, namely moderate-load RE (MOD; 4 sets of 8 repetitions at 85% 8RM), low-load RE (LOW; 4 sets of 15 repetitions at 45% 8RM), and a control (CON; no exercise), in a randomized, crossover design. Subjective appetite ratings; concentrations of ghrelin, peptide YY (PYY), and lactate; and the autonomic nervous system activity were evaluated before exercise and 1 h after exercise. The hunger and predicted food consumption ratings, and ghrelin concentrations immediately after exercise were significantly lower in the MOD and LOW trials (p < 0.05 vs. CON). The PYY and lactate concentrations immediately after exercise were significantly higher in the MOD and LOW trials (p < 0.05 vs. CON). Heart rate variability recovery was slower in the MOD trial. These findings suggest that both moderate-load and low-load RE at equal training volumes and inter-set rest induce similar responses on hunger suppression and orexigenic signals, except for the slower recovery of autonomic modulation after moderate-load RE. Our results suggest that when individuals aim to potentiate appetite suppression after a bout of RE, both moderate- and low-load RE could be applied.

Supervised high-load resistance training for improving muscle strength and quality in prediabetic older adults: A pilot randomized controlled trial.

OBJECTIVE: To investigate the effects of high- and low-load supervised, volume-matched resistance training (RT) on body composition, muscle function, and functional capacity in older adults with prediabetes. METHODS: Older adults with prediabetes were recruited and randomly assigned to high-load RT (n = 13), low-load RT (n = 12), or control groups (n = 12). RESULTS: No significant differences were observed in body composition at postintervention. High-load and low-load RT groups exhibited significant improvements in functional tests at postintervention compared with the control group. The high-load RT group exhibited a greater improvement in muscle strength and muscle quality at postintervention compared with the low-load RT group. CONCLUSION: Supervised RT is useful in the prevention of muscle functional loss in older adults with prediabetes. High-load RT is superior for enhancing muscle strength and muscle quality, despite a similar increase in functional capacity.

Effect of Progressive Resistance Training on Circulating Adipogenesis-, Myogenesis-, and Inflammation-Related microRNAs in Healthy Older Adults: An Exploratory Study.

BACKGROUND: Functional and physiological adaptations induced by resistance training have been extensively studied in older adults. However, microRNA (miRNA) as the novel regulator in protective effects remains poorly understood. OBJECTIVE: The purpose of an exploratory study was to analyze the response of a panel of circulating miRNAs to adaptations mediated by resistance training. METHODS: Ten healthy older adults (age: 67.6 ± 2.2 years, 7 women and 3 men) without previous experience in resistance training were recruited. Blood samples were collected at baseline and after a 12-week resistance training. Next-generation sequencing was used to determine circulating miRNA responses to chronic resistance training. RESULTS: After the 12-week training, physical functions including grip strength, lower body strength and endurance, and walking capacity were improved in the older adults, while the serum levels of leptin (from 18.1 ± 20.0 to 14.9 ± 17.6 ng/mL, p = 0.029) and tumor necrosis factor alpha (TNFα; from 4.4 ± 0.6 to 4.0 ± 0.6 pg/mL, p < 0.001) were significantly decreased. In addition, adipogenesis-related miRNAs (miR-103a-3p, -103b, -143-5p, -146b-3p, -146b-5p, -17-5p, -181a-2-3p, -181b-5p, -199a-5p, -204-3p, and -378c), anti-adipogenesis-related miRNAs (miR-155-3p, -448, and -363-3p), myogenesis-related miRNAs (miR-125b-1-3p, -128-3p, -133a-3p, 155-3p, -181a-2-3p, -181b-5p, -199a-5p, -223-3p, and -499a-5p), and inflammation-related miRNAs (miR-146b-3p, -146b-5p, -155-3p, -181a-2-3p, and -181b-5p) were changed significantly in the older adults after training (fold change >2, p < 0.05). The log2 fold change of miRNA-125-1-3p was inversely correlated with delta walking time (R = -0.685, p = 0.029) and change in insulin-like growth factor 1 (R = -0.644, p = 0.044). CONCLUSIONS: Our results can help explain the link between specific circulating miRNAs and beneficial effects of resistance training on functional and physiological adaptations in older adults.

A role for glutathione reductase and glutathione in the tolerance of Chlamydomonas reinhardtii to photo-oxidative stress.

The role of glutathione reductase (GR; EC 1.6.4.2) in the tolerance of Chlamydomonas reinhardtii P.A. Dangeard to high-intensity light stress (HL, 1400 µmol m-2 s-1 ) was examined. Cells survived under high light (HL) stress, although their growth was inhibited after long-term treatment (9-24 h). GR activity increased 1 h after HL treatment. The contents of total glutathione, reduced glutathione (GSH) and glutathione disulfide (GSSG) increased 1-3 h after HL treatment and then decreased after 24 h, while the GSH:GSSG ratio (glutathione redox potential) decreased after 3-9 h and recovered after 24 h. The transcript abundance of GR, CrGR1 (Cre06.g262100) and CrGR2 (Cre09.g396252) as well as glutathione synthesis-related genes, CrGSH1 (Cre02g077100.t1.1) and CrGSH2 (Cre17.g70800.t1.1), increased with a peak near 1 h after HL treatment. Except for enhanced glutathione synthesis, the GR-mediated glutathione redox machinery is also critical for the tolerance of C. reinhardtii cells to HL stress. Therefore, GR was downregulated or upregulated to investigate the importance of GR in HL tolerance. The CrGR1 knockdown amiRNA line exhibited low GR transcript abundance, GR activity and GSH:GSSG ratio and could not survive under HL conditions. Over-expression of CrGR1 or CrGR2 driven by a HSP70A:RBCS2 fusion promoter resulted in a higher GR transcript abundance, GR activity and GSH:GSSG ratio and led to cell survival when exposed to high-intensity illumination, i.e. 1800 µmol m-2 s-1 . In conclusion, GR-mediated modulation of the glutathione redox potential plays a role in the tolerance of Chlamydomonas cells to photo-oxidative stress.

Mechanistic explanation and influence of molecular structure on chemical degradation and toxicity reduction by hydroxyl radicals.

This study explored the influence of structural characteristics of organic contaminants on the degradation during an advanced oxidation process (AOP). The target contaminants were acetaminophen (ACT), bisphenol A (BPA), and tetracycline (TC). The Fenton process was selected as the model process in which major reactive species of hydroxyl radicals in most AOPs are generated for target compound degradation. The optimal reagent concentration ratio was [Fe2+]/[H2O2] = 0.5 mM/0.5 mM in an acidic condition, resulting in 83.49%, 79.01%, and 91.37% removals of ACT, BPA, and TC, respectively. Contrarily, the mineralization rates were apparently lower compared to their respective removal efficiencies. Experimental observation also suggested that the aromatic structure was rather difficult to degrade since their unsaturated electron clouds would hinder the attack of hydroxyl radicals due to electric repulsion. The preferred attacking sites of an aromatic ring differ due to the functional groups and structure symmetry. However, the electrophilic attack of the hydroxyl radical is the major reaction for decomposing aliphatic structures of cyclic or branched organics, resulting in the highest removal and mineralization of TC among these three tested chemicals. In addition, an apparent removal of a contaminant may not necessarily reduce its toxic impact on the environment.

Exploring Temporal and Intensity Effects of Resistance Exercise on Inhibition: A Four-Arm Crossover Randomized Controlled Trial.

Objective: Given the recognized benefits of resistance exercise on both physical and cognitive domains, elucidating how to maximize its benefit is pivotal. This study aims to evaluate these effects in terms of their timing and intensity on cognitive performance. Methods: This was a four-arm, crossover randomized controlled trial. Healthy college-aged male adults with recreational resistance training experience participated in this study. Participants completed three separate sessions of circuit barbell resistance exercises, including back squat, press, and deadlift. Each session corresponded to a different intensity level: 65% 1RM, 72% 1RM, and 78% 1RM. Each session consisted of 5 repetitions across 3 sets, with a 3-minute rest between exercises and sets. For the control condition, participants engaged in a reading activity for the same duration. The subjective exercise intensity was measured using the rating of perceived exertion and repetitions in reserve immediately after each set. The primary outcome was the temporal effect of acute resistance exercise on inhibition, measured by the Stroop color-word task. The secondary outcome was the effect of different intensities. Results: 30 out of 31 recruited participants were randomized, with 28 completing all experiment sessions. Using repeated measures correlation (rrm), a linear temporal effect was observed on accuracy-adjusted congruent reaction time: rrm = 0.114, p = 0.045, 95% CI [0.002, 0.223]. Participants responded 19.1 ms faster than the control condition approximately 10 minutes post-intervention. This advantage, however, gradually declined at a rate of 4.3 ms every 15 minutes between 10-55 minutes post-intervention. In contrast, no significant effects were detected for incongruent trials or the Stroop effect. When examining the linear relationship across exercise intensities, no significant correlations emerged for congruent trials. Conclusion: Resistance exercise demonstrates a temporal effect on cognitive performance, particularly in reaction speed for congruent trials, without significant changes in incongruent trials or the overall Stroop effect. The findings highlight the importance of timing in leveraging the cognitive benefits of acute resistance exercise, suggesting a window of enhanced cognitive performance following exercise. However, this study has a limitation regarding Type I error inflation, due to multiple measurements of cognitive performance being undertaken, suggesting caution in interpreting the observed temporal effects. Practically, scheduling crucial, cognitively demanding tasks within 10-60 minutes post-exercise may maximize benefits, as positive effects diminish after this period.

Effects of resistance exercises on inhibitory control and plasma epinephrine levels: A registered report of a crossover randomized controlled trial.

According to the locus coeruleus-norepinephrine (LC-NE) theory, activity of the LC, the major releaser of NE in the brain, regulates inhibitory control. As there is reciprocal communication between circulating epinephrine and the LC, plasma epinephrine is used as the index of LC-NE activity. The aim of this crossover randomized controlled trial is to expand on previous findings by investigating the effects of free-weight, multiple-joint, and structural barbell resistance exercises. Previous studies have had some methodological limitations, such as failure to report the process of randomization, absence of resistance exercise familiarization before the maximal strength testing, and lack of protocol publication. To address these issues, this study incorporates resistance exercise familiarization, transparent reporting of randomization, and submission as a registered report. The results suggest that a single session of resistance exercise (barbell squat, press, and deadlift) with an intensity of 65%-78% 1RM for five repetitions (70%-90% relative intensity) and three sets with 3-min rest intervals improved Stroop congruent reaction time (RT) only (t(27) = -2.663, mean reduction = -15 ms, p = .013, 95% CI [-26, -3]). No significant enhancements were observed in Stroop incongruent RT, inhibitory control as indexed by Stroop effect, or inhibitory control as indexed by the RT difference between the Stroop task and the simple reaction task. Moreover, the alterations in plasma epinephrine levels did not significantly associate with changes in any measure of cognitive performance.

Activation of inflammatory pathways in PBMCs linking type 2 diabetes in older adults without obesity.

The mechanism that underlies the dysregulation of glucose metabolism in older adults without obesity has yet to be thoroughly understood. This study investigated the risk of developing Type 2 diabetes (T2D) in older adults without obesity (BMI: 18.5 to <25 kg/m2). Data on glucose levels (measured by an oral glucose tolerance test), body composition, physical activity level, lipid profile, inflammatory cytokines, and nuclear factor kappa B (NF-κB) and Sirtuin 1 (SIRT1) signaling pathways in peripheral blood mononuclear cells (PBMCs) in older adults with normal glucose tolerance (NGT, n = 17) and those with prediabetes (n = 20) or T2D (n = 8) were gathered. As expected, participants with T2D exhibited higher insulin resistance; ß-cell dysfunction; and higher levels of triglycerides and tumor necrosis factor-α (TNF-α) than those with NGT. No differences in physical activity, lean mass, body fat, or cholesterol were observed between the NGT, prediabetes, and T2D groups. Downregulation of SIRT1 and activation of NF-κB signaling in PBMCs were observed in the T2D group. Increased phosphorylation of NF-κB and low SIRT1 protein expression in PBMCs were associated with insulin resistance and ß-cell dysfunction. NF-κB and its upstream inhibitor IκBα were positively and inversely correlated with TNF-α, respectively. SIRT1 expression was positively correlated with IL-10. Activation of NF-κB signaling pathways and downregulation of SIRT1 in PBMCs were associated with the inflammatory milieu in older adults without obesity.

Effects of volume-matched resistance training with different loads on glycemic control, inflammation, and body composition in prediabetic older adults.

The purpose of the investigation was to examine the influence of resistance training (RT) with equal volume and varying load on glycemic control, inflammation, and body composition in non-obese prediabetic older adults. Non-obese older adults with prediabetes were randomized into 2 groups, high-load (80% of 1RM) and low-load (40% of 1RM) RT (n = 12/group), both with the same training volume. Oral glucose tolerance test (OGTT) and blood samples were collected at baseline and again after 10 weeks of RT. Fasting blood glucose (103.8 vs. 99.9 mg/dL) and the area under the curve (AUC) of OGTT (0-30 min) decreased significantly in older adults with prediabetes after 10 weeks of volume-matched RT (p < 0.05). Serum levels of MCP-1 (138.7 vs. 98.5 pg/mL) and TNF-α (1.8 vs. 1.3 pg/mL) showed significant decrease after 10 weeks of high-load RT (p < 0.05). There were no changes in IL-10, IL-6, and CRP levels in both groups. Leptin showed significant decrease after 10 weeks of low-load RT (p < 0.05). Changes in fasting glucose and AUC of OGTT (0-120 min) were positively correlated with changes in MCP-1 and TNF-α (p < 0.05). Lean body mass (39.6 vs. 40.3 kg) increased significantly after 10 weeks of volume-matched RT (p < 0.05). Results indicate that equal-volume RT at different loads is beneficial to glycemic control and muscle growth, and high-load RT shows more prominent anti-inflammatory effects. Novelty: Short-term high-load resistance training can help older adults bring their blood sugar level back to normal. High-load resistance training attenuates aging-associated chronic inflammation.

Comparing machine learning with case-control models to identify confirmed dengue cases.

In recent decades, the global incidence of dengue has increased. Affected countries have responded with more effective surveillance strategies to detect outbreaks early, monitor the trends, and implement prevention and control measures. We have applied newly developed machine learning approaches to identify laboratory-confirmed dengue cases from 4,894 emergency department patients with dengue-like illness (DLI) who received laboratory tests. Among them, 60.11% (2942 cases) were confirmed to have dengue. Using just four input variables [age, body temperature, white blood cells counts (WBCs) and platelets], not only the state-of-the-art deep neural network (DNN) prediction models but also the conventional decision tree (DT) and logistic regression (LR) models delivered performances with receiver operating characteristic (ROC) curves areas under curves (AUCs) of the ranging from 83.75% to 85.87% [for DT, DNN and LR: 84.60% ± 0.03%, 85.87% ± 0.54%, 83.75% ± 0.17%, respectively]. Subgroup analyses found all the models were very sensitive particularly in the pre-epidemic period. Pre-peak sensitivities (<35 weeks) were 92.6%, 92.9%, and 93.1% in DT, DNN, and LR respectively. Adjusted odds ratios examined with LR for low WBCs [≤ 3.2 (x103/µL)], fever (≥38°C), low platelet counts [< 100 (x103/µL)], and elderly (≥ 65 years) were 5.17 [95% confidence interval (CI): 3.96-6.76], 3.17 [95%CI: 2.74-3.66], 3.10 [95%CI: 2.44-3.94], and 1.77 [95%CI: 1.50-2.10], respectively. Our prediction models can readily be used in resource-poor countries where viral/serologic tests are inconvenient and can also be applied for real-time syndromic surveillance to monitor trends of dengue cases and even be integrated with mosquito/environment surveillance for early warning and immediate prevention/control measures. In other words, a local community hospital/clinic with an instrument of complete blood counts (including platelets) can provide a sentinel screening during outbreaks. In conclusion, the machine learning approach can facilitate medical and public health efforts to minimize the health threat of dengue epidemics. However, laboratory confirmation remains the primary goal of surveillance and outbreak investigation.